The invention relates to a process by way of which ceramic materials, namely tiles and similar products, can be fired at fast production tempo; a kiln for implementation of such a process is also disclosed.
The ceramics art field is known to embrace high speed firing methods, as used for tiles in particular, for which roller hearth kilns are employed. Tiles are conveyed through the kiln in a continuous stream, with the firing cycle occurring during their passage from end to end. Temperatures are exactingly distributed along the longitudinal axis of the kiln between entry and exit points, and can be depicted graphically as a steady curve comprising an initial rise, an intermediate stretch during which maximum temperature is reached, and a final drop. Thus, proceeding through the kiln, the ceramic material is subjected to ever-increasing temperature values in the pre-heat stage, fired during its passage through the maximum temperature stretch, and then exposed to progressively decreasing temperatures before finally exiting.
In order to implement firing cycles of the kind in question, the kiln must necessarily be of a given length, inasmuch as its longitudinal dimension is directly related to and dependent upon the temperature curve to be produced inside the enclosure.
An additional drawback with conventional kilns is that they do not permit of creating mixed treatment conditions -e.g. controlled atmosphere, in the course of the material's being fired.
The object of the invention disclosed is that of overcoming the drawbacks mentioned above.